Exposed wood + water is a bad thing, so when I noticed the wood post holding up our patio going into the wet ground, I knew something had to be done. I’ll show you how I protected our exposed wood from water.
We love our patio cover. It turns our patio into a second family room, especially in the summer. As we’ve worked on improving out backyard, we mostly ignored the patio cover because it seemed to be in great condition. Until we noticed this.
Dirt on exposed wood is not a good thing, specifically dirt that gets wet regularly, like in our planter. Termites, rot, and other unpleasantness happen, and the wood slowly breaks down and falls apart.
Our patio cover is structurally sound, and we want to keep it that way for years to come, so we had to do something to protect the wood post from water in the planter.
Remove the dirt around the wood post
The first thing we did was to remove all of the dirt around the post. This temporarily stopped any problems and let us look at the wood to see if there was any water or insect damage. Luckily the wood was in pretty good shape. We also found that there was a cement footing at the bottom, it just didn’t come high enough to protect the wood inside the planter around the post. Maybe the planter was put in later.
We actually left the post like this for several weeks while we researched and decided what to do to protect the wood. We talked with a good friend who has been a general contractor for more than 60 years and decided to follow his advice on protecting the wood.
Clean the exposed wood
I used a scrub brush and a then a toothbrush to clean off all the dirt and a few small roots that were stuck on the wood post. Then I used a damp rag to clean anything that was left and let the post dry
Spray flex seal
Our contractor friend suggested Flex Seal as a way to seal the wood against any water damage. Flex seal is a rubbery coating that sprays on as a liquid and dries to a flexible barrier. It’s usually used to seal leaks and fill holes. It creates a watertight bond. Perfect for sealing our wood against water damage. I sprayed 2 coats on the bottom foot of the post and on the base, allowing time to dry between coats.
Cover with plastic sheeting
the base to 6 inches above where the dirt will come. A total of 10 inches. The 6 inches of plastic that sticks out above ground may not look wonderful, but it’s important to protect the wood just above the dirt.
I sprayed one more coat of Flex Seal to make the post sticky, then wrapped the plastic sheeting around the post tightly. It wrapped around about 6 times, so I stapled it every once in a while to keep it tight. I also stapled it several times at the end. Then I coated it with one more coat of Flex Seal.
Add silicone caulking
Even though the plastic sheeting was tightly wrapped, I could see there were still small gaps between the plastic and the wood. So, I spread silicone caulking around the top and bottom of the plastic and the end to seal it more thoroughly. I use a clear exterior caulking that went on white and turned clear as it dried.
When the caulking was dry, I covered the bottom of the post with dirt again and leveled out the dirt in the planter.
With the wood now completely protected, I hid the unsightly black plastic with a plant for now. One day soon we plan to paint the entire patio cover, including this post. That will hide the plastic even more. And a few inches of black plastic is worth having a structurally sound patio cover.